Subwoofer placement or suggestions

Hi all- new here.
I just bought a 2012 Keystone Laredo 303TG and it came with an Estone EX8500 DVD/radio entertainment unit. I dont know if its a true surround sound system but it does have 4 speakers inside the trailer and 2 outside. I am trying to figure out if the Laredo comes with a subwoofer because the EX8500 doesnt seem to have a quality bass sound but does have an rca type port for a subwoofer. Maybe its just not hooked up? Does anyone know where the subwoofer would be located in the trailer? After looking around the trailer I dont see where a good place to put one would be if I have to buy one. Any suggestions?

I am not sure about travel trailers but all the 5th wheels I have seen the subwoofers are usually in the entertainment center below the TV or behind the fireplace. I am not sure a subwoofer would be a stock/standard item but your purchase spec sheet might tell you.